We are requesting five postdoctoral positions for focused research training for pediatricians in subspecialty training in pediatrics. Children's Hospital Medical Center is one of the largest full service pediatrics training programs in the world, with extensive institutional and extramural support for state-of-the-art research. The Children's Hospital Medical Center presently has over 100 pediatricians in subspecialty training and has programs for supporting junior faculty development that include a Child Health Research Career Development Award and Proctor Fellowships. However, a well-recognized deficit in the research training of pediatric subspecialists is an inadequate high quality research experience to prepare trainees to successfully develop academic careers. These training positions will be used to support the third research year of the subspecialty fellowship and an extra fourth year of intensive research modeled after the Pediatric Scientist Development Program. A focused effort will be made to support trainees from divisions without training grants in laboratories with the infrastructure to effectively mentor academic development. All fellows will be encouraged to initiate significant research experiences utilizing the faculty mentors for this T32. The Executive Committee (Drs. Boat, Jobe, Daniels, and Williams) will select fellows for support after they have demonstrated the potential and motivation during the first two years of fellowship training. The fellows will have a training committee headed by their mentor to track their progress. The program will provide an intensively mentored fellowship research experience for a full two years after the initial two years of clinical fellowship. The goal is to prepare the subspecialist to transition successfully to the K08 award or the other faculty development opportunities at Children's Hospital Medical Center.